Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans.
What this study found
Long-term CLA supplementation reduced body fat mass compared with placebo, with similar fat-loss effects for CLA-free fatty acid and CLA-triacylglycerol. From month 0 to 12, body fat mass changed by 0.2 kg with placebo, -1.7 kg with CLA-free fatty acid, and -2.4 kg with CLA-triacylglycerol; body fat mass was significantly lower in both CLA groups versus placebo at 12 months (P = 0.001). CLA-free fatty acid also increased lean body mass relative to placebo, with a 0.7 kg increase versus 0.0 kg and 1.8% greater lean body mass than placebo (P = 0.002), and lean body mass was significantly…
- Study & population
- Randomized, double-blind, placebo-controlled trial in healthy overweight adults in Norway.
- Intervention
- Participants received oral conjugated linoleic acid for 12 months as 6 softgel capsules daily.
- Key limitation
- The trial was modest in size, with about 60 participants per active arm, and it was conducted in a single country, which may limit generalizability.
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Open PDFOriginal abstract
BACKGROUND Short-term trials showed that conjugated linoleic acid (CLA) may reduce body fat mass (BFM) and increase lean body mass (LBM), but the long-term effect of CLA was not examined. OBJECTIVE The objective of the study was to ascertain the 1-y effect of CLA on body composition and safety in healthy overweight adults consuming an ad libitum diet. DESIGN Male and female volunteers (n = 180) with body mass indexes (in kg/m(2)) of 25-30 were included in a double-blind, placebo-controlled study. Subjects were randomly assigned to 3 groups: CLA-free fatty acid (FFA), CLA-triacylglycerol, or placebo (olive oil). Change in BFM, as measured by dual-energy X-ray absorptiometry, was the primary outcome. Secondary outcomes included the effects of CLA on LBM, adverse events, and safety variables. RESULTS Mean (+/- SD) BFM in the CLA-triacylglycerol and CLA-FFA groups was 8.7 +/- 9.1% and 6.9 +/- 9.1%, respectively, lower than that in the placebo group (P < 0.001). Subjects receiving CLA-FFA had 1.8 +/- 4.3% greater LBM than did subjects receiving placebo (P = 0.002). These changes were not associated with diet or exercise. LDL increased in the CLA-FFA group (P = 0.008), HDL decreased in the CLA-triacylglycerol group (P = 0.003), and lipoprotein(a) increased in both CLA groups (P < 0.001) compared with month 0. Fasting blood glucose concentrations remained unchanged in all 3 groups. Glycated hemoglobin rose in all groups from month 0 concentrations, but there was no significant difference between groups. Adverse events did not differ significantly between groups. CONCLUSION Long-term supplementation with CLA-FFA or CLA-triacylglycerol reduces BFM in healthy overweight adults.